A Cake Moment for the Electric Vehicle
But is it “You can have your cake and eat it too,” or is it “Let them eat cake” ?
First things first, the proper definitions. Far too many journalists with degrees in the Arts are writing about a subject they have no clue about. Proof? Just ask them what is the difference between a kilowatt (kW) and a kilowatt-hour (kWh)? At best you will get a blank stare. At worst, far too many think Energy and Power are interchangeable words for electricity, that a kilowatt is just an abbreviation for a more formal kilowatt-hour. Wrong. If you want to watch them get completely tongue-tied, ask why kilowatts are multiplied by time (kWh) but BTUs are instead divided by time (BTU per hour, BTU/hr)? Do they even know that BTU stands for British Thermal Unit, and what is that anyways?
The answers are best written by those with degrees in the Sciences, hence engineering.
So as briefly and simply as possible:
Power, kilowatts (kW), and BTUs per hour (BTU/hr), are rates. Just like speed, the miles per hour (MPH) driving a car, or the gallons per minute (GPM) of water through a hose.
Energy, kilowatt-hours (kWh), and BTUs, are both specific physical units, of the ability to do work or provide heat. Just like the physical units of distance (miles) or volume (gallons).
Like measuring temperature in degrees Fahrenheit (°F) or Celsius (°C) it is the same point, just a different scale. You can measure a certain distance in kilometers, or miles, or feet, but it remains the same length. Similarly You can measure a given volume in cubic meters, cubic feet, or cubic inches, still all the same. And energy whether measured in kWh or BTU still will do the same work or provide the same heat.
Quiz time.
1) Marionette is driving her car at a speed of 70 MPH. How far does she get?
2) The garden hose water flows at 3 GPM. The fire truck pumps water out at 24 GPM. How long does it take to fill the swimming pool?
Of course you can’t answer those two questions. You need more information, the other unit of the rate, time in the first question, volume in the second.
So when an article says “converting 10 kWh to kW,” or something to the effect of “a 10 kWh solar array is 240 kW of electricity saved,” just toss out the article.
The reason for the above description is that too many articles about Electric Vehicles (EVs) are making terrible, impossible calculations.
The Real EV Numbers
Americans are very familiar with the MPG of cars. They hear it everywhere from manufactures, journalists and the media, the government, even the dashboards of modern cars. 15 to 20 MPG for pickup trucks and big SUVs, 20-25 MPG for medium and compact SUVs, 25-30 MPG for full to mid-size cars, 30-35 MPG for compact cars, and 35-40 MPG for hybrid vehicles is fairly well known. But electric cars don’t use gallons of electricity, so how can they possibly compare?
It is called the Gallons of Gasoline Equivalent (GGE) and it directly equates gallons with kWh. So once the rate that electricity consumed by an EV is determined, kWh per mile, it can be directly converted to MPG. For the mathematically inclined, the U.S. GGE of E-10 gasoline (10% ethanol) is 32.8 kWh/gallon.
EVs of 2020 and earlier get 80 to 100 MPG-e. For 2022 there are 10 EVs for sale, note only 3 of which are from Tesla as the market grows, that get 115 to 130 MPG-e as tested by the EPA (30 to 25 kWh per hundred miles.) That is a tremendous improvement over gasoline vehicles with Internal Combustion Engines (ICE).
So a 120 MPG-e average 2022 model year EV certainly must be head and shoulders better than a 20, 30, even 40 MPG conventional gasoline vehicle, right? As we learned above, you need another variable, in this case the cost of the fuel. Americans are acutely aware of the cost of gasoline in $ per gallon.
Not as well known is the units of your electric bill of dollars, per, what? Oh, those watt-things. That unit is kilowatt-hours (kWh). You might see a base charge, stranded charge, delivery fee, and a myriad of other charges. All that matters is the bottom line. Just simply divide your total bill, maybe about $200, by the total kWh used, roughly 1,000 kWh. The result is an electricity cost of $0.20 or 20¢ per kWh.
That U.S. average 20¢/kWh electricity directly equates (by that GGE) to a gasoline price of $6.50 per gallon. Wait a minute. $6.50/gallon? Only two years ago it was $2.50/gallon. Even in 2008 and again in 2012 it was under $4.50 a gallon.
And 20¢/kWh is only average. The Northeast (at worst Massachusetts) and California are 24¢ (per kWh). Time of Day (ToD) electric rates can go to 30¢. And when traveling any distance using charging stations (as opposed to your house, assuming you don’t live in an apartment) can easily top 40¢. Double, or the equivalent of $13.00 per gallon of gasoline. In short, the EV better darn well better get higher milage because it’s fuel costs a lot more. Unless you live in the south or west, with 10¢ electricity.
Also, this is average milage. Using air conditioning in hot summer days or heating in the frigid winter also drains the battery instead of scavenging off the ICE. So does enjoying the power to accelerate at “Ludicrous “ rates under your right foot. In May of 2021, Car an Driver tested a 2020 Porsche Taycan 4S and a Tesla Model S Long Range Plus, at the same time on the same course. The $105,150 base price Porsche had an EPA rating of 77/75/81 combined/city/highway and a 83.7 kWh battery pack. The $70,620 base price Tesla was rated 117/121/112 with a 103.9 kWh battery. On a fixed 75 MPH closed-loop test, the Porsche achieved 77 MPG-e and a highway range of 220 miles, exactly as rated. The tesla on the other hand only achieved 102 MPG-e and a range of 320 miles. Better than the Porsche, but still a significant 13% less than the EPA rating.
The conclusion? It depends on where you live, how you drive, and where you recharge an EV to determine the monthly operating cost. How can an average mathphobic consumer possibly compare an EV to traditional ICE to determine energy savings? Durable appliances in the U.S. come with a big yellow sticker with the annual energy cost, even going so far as to state the electric rate used. Why not automobiles too? Gasoline prices might vary widely from $4 to $7 a gallon as of this writing with the Ukrainian war happening, but that is nowhere near the 10¢ to 40¢ range of electricity, which equates to $3.25 to $13 a gallon.
The foremost question becomes, who is purchasing a $60,000 to $120,000 vehicle in the first place to save money monthly, or do they only “feel better“ about spending less on electricity instead of gasoline?
When gasoline was $2.50 and a lightly used Toyota Corolla or Honda Civic or similar 35-40 MPG economy car could be purchased for $15,000 or less, the monthly fuel cost was $60 to $70. Just to match this required a 75-80 MPG-e EV and electricity under the national average, at 15¢. The only EV that could match the capital cost would be a used 2011-2017 Nissan Leaf with a 24 kWh battery, yet it would have a range of only 73 to 84 miles. A 2016–2017 Leaf with the larger 30 kWh battery would have a slightly improved range of 84 miles. While useful for most daily commutes, it is useless, and also small, for weekend excursions.
But with supply chain constraints from Covid-19, the 2021 average price of a new car suddenly tops $44,000 $43,000 for a non-luxury vehicle, and $47,000 for a luxury vehicle according to Kelly Blue Book, which is typically a loaded Compact SUV such as the best-selling Toyota RAV4 or the Honda CR-V, the highly rated Mazda CX-5, or the Hyundai Santa Fe, Kia Sorento, Nissan Rogue, Subaru Forester, Ford Escape, Chevy Trailblazer, and Volkswagen Tiguan that start around $30,000 but are typically optioned much higher. The Mid-size SUVs such as Toyota Highlander or the Honda Pilot or Passport, the highly rated Kia Telluride and Hyundai Palisade, or the Mazda CX-9, Nissan Murano, popular Ford Explore and Subaru Outback, Chevy Traverse, Jeep Grand Cherokee, and Volkswagen Atlas (none of which are luxury brands the likes of BMW, Cadillac, or Mercedes-Benz,) start at $40,000 and can easily reach over $55,000. The mid-size vehicles are 20-25 MPG, with the compacts being 25-30 MPG.
At 2021 gas prices of $3.00 per gallon, these SUVs cost $100 to $150 per month to gas up. With March 2022 gas prices flirting with $5, they now cost $160 to $250 a month, $200 to $300 if gas hits $6.
In 2022, the comparably sized electric SUVs range from $35,000 to a Hyundai Kona EV and the (temporarily on hold due to battery fires, not a small problem) Chevy Bolt EV and EUV, to the $60,000 Tesla Model Y and have an EPA combined efficiency of 110 to 120 MPG-e. At widely varied, but still not extreme, electric rates of 15¢ to 30¢, the cost to charge up the EV is from $40 to $90 for the month.
Simply put, the wealthy don’t care about the cost of charging because their 4-door Tesla Model S Plaid or Porsche Taycan 4S is substantially faster than a 2-passenger Corvette or even a Ferrari. The mass-affluent that can afford a $50,000 vehicle can actually save on fueling charges, however, the fuel savings are nowhere near the $500 monthly lease or loan payment. The EV might indeed save cash flow, yet it is at the greater expense of capital. Because it reduces CO2 emissions (yet, where does the electricity come from?) and lowers monthly fueling costs, apart from the economics, it “feels good” to do something for the environment and save on costs at the same time, getting your cake and eating it too.
And batteries are simply still too expensive. For those just getting by, such as entry-level professionals, and the working poor, certainly have a long way to go before an EV can save them both capital costs and monthly fuel expenses. Paying an extra $10,000 to $12,000 for an EV to save $100 per month is a poor 10 year ROI, even before considering loan interest. What of those who simply cannot afford to purchase an EV?
CBS television late night comedian Stephen Colbert, who is paid $15 million annually, recently quipped “he doesn’t care if gas gets to $15 because he drives a Tesla,” for which he was roundly criticized. This was clearly the “let them eat cake” moment for EV proponents.
Back in the real world, for the middle-class, it is not yet a win-win. Many companies, not just Tesla, are working hard to provide consumers with EVs that are affordable, with small to no price-premium over a similar ICE vehicle, and pocketable monthly refueling expenses. Their victory cannot come soon enough.
(The following piece reviews the fuel economy and cost of various EVs and PHEVs, as there is more than just Tesla in this market sector.)
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The following table lets anyone see what a gasoline or EV costs to fuel or charge-up every month.
Remember that different unit scales still mean the same thing. Just as 32 °F = 0 °C, or 10 miles = 16 km, or 120 seconds = 2 minutes, 90 minutes = 1-½ hours, or 1 Gallon = 128 ounces = 3.785 liters, the same can be said of efficiency.
100 MPG-e = 3.0 miles per kilowatt-hour = 32.8 kilowatt-hours per hundred miles.
Use whichever scale you have available, although the most widely reported and known is MPG or MPG-e.
Pick the ROW of the MPG of the vehicle and look across.
Pick the COLUMN of the fuel cost and look down. If you don’t know your electricity cost, simply divide your total electric bill, about $200, by the total kWh used, roughly 1,000 kWh. The result is an electricity cost of $0.20 or 20¢ per kWh. Note public charging stations such as Electrify America cost 30¢ to 40¢ per kilowatt-hour (¢/kWh). Or see average state residential rates in this table:
The INTERSECTION is the cost for driving an average 1,000 miles per month.
Tables and Images by author, except as noted.